In high-pressure discharge lamps light is generated with a passage of current through a gas or metal vapor plasma in a sealed discharge vessel. Ions, electrons and neutral particles exist side by side in the plasma in the basic state and in the excited state, with the electrons absorbing energy in the electrical field and transmitting the discharge to the atoms or molecules by way of an impact. Atoms or molecules are excited in the process and the energy released during the return to the basic state is emitted as radiation characteristic of the relevant atom or molecule. These typically pressure-broadened emission lines are particularly disadvantageous in applications which require exact color reproduction or a complete spectrum, as, by way of example, a Planck radiator exhibits.